I believe the company didn't have to define it is special. In this case the 25% rule takes precedence over anything else, special or regular, which COR or the selling entity overlooked.
" FINRA (Financial Industry Regulatory Authority) establishes all stock trading rules for all U.S. stock exchanges and there are only two sets of dividend date rules for U.S. publicly traded companies -- one for normal distributions, which are dividends or distributions that represent less than 25% of the stock's trading price, and the other for dividends or distributions equal to or exceeding 25% of the stock's trading price. From FINRA's website, those two sets of rules are as follows:
(1) In respect to cash dividends or distributions, or stock dividends, and the issuance or distribution of warrants, which are less than 25% of the value of the subject security, if the definitive information is received sufficiently in advance of the record date, the date designated as the "ex-dividend date" shall be the second business day preceding the record date if the record date falls on a business day, or the third business day preceding the record date if the record date falls on a day designated by the Committee as a non-delivery date.
(2) In respect to cash dividends or distributions, stock dividends and/or splits, and the distribution of warrants, which are 25% or greater of the value of the subject security, the ex-dividend date shall be the first business day following the payable date."